style: remove selector_map::find_push.
style: remove selector_map::find_push.

It has a single caller and is overly generic, which is going to make harder to
add fallible allocations to it.

pyfisch/servo,paulrouget/servo,avadacatavra/servo,thiagopnts/servo,jimberlage/servo,sadmansk/servo,fiji-flo/servo,SimonSapin/servo,splav/servo,dati91/servo,anthgur/servo,notriddle/servo,ConnorGBrewster/servo,saneyuki/servo,szeged/servo,notriddle/servo,szeged/servo,nnethercote/servo,thiagopnts/servo,jimberlage/servo,larsbergstrom/servo,avadacatavra/servo,splav/servo,peterjoel/servo,notriddle/servo,rnestler/servo,emilio/servo,emilio/servo,larsbergstrom/servo,nnethercote/servo,dati91/servo,splav/servo,pyfisch/servo,splav/servo,szeged/servo,eddyb/servo,pyfisch/servo,fiji-flo/servo,jimberlage/servo,saneyuki/servo,DominoTree/servo,mbrubeck/servo,DominoTree/servo,ConnorGBrewster/servo,anthgur/servo,ConnorGBrewster/servo,thiagopnts/servo,szeged/servo,peterjoel/servo,avadacatavra/servo,notriddle/servo,SimonSapin/servo,splav/servo,SimonSapin/servo,emilio/servo,saneyuki/servo,KiChjang/servo,DominoTree/servo,notriddle/servo,peterjoel/servo,nnethercote/servo,upsuper/servo,szeged/servo,DominoTree/servo,dati91/servo,anthgur/servo,CJ8664/servo,canaltinova/servo,mattnenterprise/servo,mbrubeck/servo,eddyb/servo,eddyb/servo,upsuper/servo,canaltinova/servo,mattnenterprise/servo,dsandeephegde/servo,eddyb/servo,cbrewster/servo,notriddle/servo,szeged/servo,mattnenterprise/servo,CJ8664/servo,upsuper/servo,nnethercote/servo,dsandeephegde/servo,CJ8664/servo,paulrouget/servo,cbrewster/servo,eddyb/servo,KiChjang/servo,saneyuki/servo,emilio/servo,eddyb/servo,avadacatavra/servo,pyfisch/servo,paulrouget/servo,KiChjang/servo,larsbergstrom/servo,peterjoel/servo,sadmansk/servo,KiChjang/servo,mattnenterprise/servo,anthgur/servo,mattnenterprise/servo,dsandeephegde/servo,larsbergstrom/servo,rnestler/servo,cbrewster/servo,DominoTree/servo,cbrewster/servo,splav/servo,paulrouget/servo,thiagopnts/servo,splav/servo,pyfisch/servo,jimberlage/servo,paulrouget/servo,mbrubeck/servo,rnestler/servo,jimberlage/servo,thiagopnts/servo,saneyuki/servo,eddyb/servo,fiji-flo/servo,dati91/servo,thiagopnts/servo,avadacatavra/servo,rnestler/servo,dati91/servo,eddyb/servo,emilio/servo,szeged/servo,cbrewster/servo,sadmansk/servo,larsbergstrom/servo,peterjoel/servo,notriddle/servo,szeged/servo,paulrouget/servo,DominoTree/servo,mbrubeck/servo,upsuper/servo,SimonSapin/servo,upsuper/servo,pyfisch/servo,peterjoel/servo,dsandeephegde/servo,KiChjang/servo,dati91/servo,rnestler/servo,KiChjang/servo,emilio/servo,notriddle/servo,sadmansk/servo,dsandeephegde/servo,SimonSapin/servo,rnestler/servo,avadacatavra/servo,thiagopnts/servo,splav/servo,KiChjang/servo,avadacatavra/servo,CJ8664/servo,saneyuki/servo,DominoTree/servo,sadmansk/servo,rnestler/servo,peterjoel/servo,nnethercote/servo,notriddle/servo,DominoTree/servo,nnethercote/servo,fiji-flo/servo,KiChjang/servo,thiagopnts/servo,larsbergstrom/servo,dsandeephegde/servo,ConnorGBrewster/servo,fiji-flo/servo,anthgur/servo,pyfisch/servo,CJ8664/servo,emilio/servo,szeged/servo,larsbergstrom/servo,nnethercote/servo,CJ8664/servo,mattnenterprise/servo,dati91/servo,dsandeephegde/servo,jimberlage/servo,szeged/servo,SimonSapin/servo,cbrewster/servo,larsbergstrom/servo,nnethercote/servo,KiChjang/servo,ConnorGBrewster/servo,saneyuki/servo,saneyuki/servo,CJ8664/servo,cbrewster/servo,mbrubeck/servo,splav/servo,sadmansk/servo,paulrouget/servo,canaltinova/servo,larsbergstrom/servo,peterjoel/servo,CJ8664/servo,nnethercote/servo,paulrouget/servo,saneyuki/servo,pyfisch/servo,mbrubeck/servo,upsuper/servo,ConnorGBrewster/servo,ConnorGBrewster/servo,mattnenterprise/servo,paulrouget/servo,pyfisch/servo,DominoTree/servo,nnethercote/servo,DominoTree/servo,canaltinova/servo,jimberlage/servo,pyfisch/servo,canaltinova/servo,emilio/servo,saneyuki/servo,rnestler/servo,KiChjang/servo,jimberlage/servo,ConnorGBrewster/servo,upsuper/servo,upsuper/servo,cbrewster/servo,dsandeephegde/servo,dati91/servo,canaltinova/servo,mbrubeck/servo,anthgur/servo,mattnenterprise/servo,peterjoel/servo,sadmansk/servo,larsbergstrom/servo,sadmansk/servo,splav/servo,notriddle/servo,jimberlage/servo,canaltinova/servo,paulrouget/servo,anthgur/servo,emilio/servo,mbrubeck/servo,fiji-flo/servo,SimonSapin/servo,fiji-flo/servo,anthgur/servo,avadacatavra/servo,emilio/servo,fiji-flo/servo,SimonSapin/servo,canaltinova/servo,peterjoel/servo